The present invention pertains generally to fluid controlling valves of the plug type having multiple seals in place on the rotary plug member.
In the prior art, several valve embodiments utilize continuous seals such as O-rings to prevent fluid passage between a plug member wall and adjacent wall of a valve housing. Examples of such prior art valves are found in U.S. Pat. Nos. 3,133,723; 3,168,280; 3,360,236; 3,991,975; and 4,031,918. For the most part the foregoing valve examples are two-way valves with the plug member having open and closed positions with a transverse opening communicating ports on opposite sides of a valve housing. The O-ring seals of such valves may be of elongate, rectangular or oval configuration as determined by the size and shape of the valve housing port being sealed. Further, such O-ring seals are symmetrically disposed on the plug member. The last mentioned above patent utilizes O-rings in place on a plug member that has the capability of simultaneously communicating two pairs of valve ports with the O-rings and plug member defining arcuate passageways between ports.